Dementia is a condition that slowly changes how the brain works, especially when it comes to thinking, remembering, and solving problems. When someone has dementia, their brain’s ability to handle everyday challenges, like making decisions or figuring out what to do next, becomes weaker. This happens because dementia damages the brain’s networks, which are groups of brain regions that work together to help us think clearly and solve problems. These networks are not just random parts of the brain; they are organized systems that allow different regions to communicate and share information. When dementia starts, these networks begin to break down, making it harder for the brain to do its job.
One of the most important networks for problem solving is called the executive function network. This network is mainly found in the front part of the brain, especially in an area called the prefrontal cortex. The executive function network helps us plan, make decisions, control our impulses, and switch between tasks. When dementia begins, this network is often one of the first to be affected. Studies show that people with early dementia have trouble with tasks that require planning or organizing, like figuring out how to cook a meal or manage money. This is because the connections between brain regions in the executive network start to weaken, making it harder for the brain to send signals and coordinate actions [2].
As dementia progresses, the damage spreads to other parts of the brain. The default mode network, which is active when we are not focused on the outside world but instead thinking about ourselves or our memories, also becomes disrupted. This network is important for self-reflection and internal thought, but it also plays a role in problem solving by helping us connect past experiences to new situations. When the default mode network is damaged, people with dementia may struggle to use their memories to solve problems or make decisions. For example, they might forget how they solved a similar problem in the past, making it harder to find a solution now [1].
Another network that is affected by dementia is the salience network. This network helps the brain decide what is important and what to pay attention to. It is mainly found in the front and side parts of the brain, including the insula and anterior cingulate cortex. When the salience network is damaged, people with dementia may have trouble focusing on the right information or ignoring distractions. This can make problem solving even more difficult, as they might get stuck on unimportant details or miss key clues that could help them find a solution [1].
In addition to these specific networks, dementia also affects how different networks communicate with each other. The brain relies on a system of connections called functional connectivity, which allows different networks to work together. When dementia damages these connections, the brain’s networks become less coordinated. This means that even if one network is still working, it may not be able to share information with other networks, making it harder to solve complex problems that require input from multiple brain regions [1].
One of the most noticeable changes in dementia is the shift in which networks are most important for thinking and problem solving. In the early stages of dementia, the executive function network is usually the most active and important for problem solving. However, as the disease progresses, the memory network becomes more central. This means that people with dementia start to rely more on their memories to solve problems, even though their memory is also declining. This shift can make problem solving even more challenging, as they may struggle to remember how to do things or forget important details that could help them find a solution [2].
Dementia also affects the brain’s ability to adapt and reorganize itself. Normally, the brain can change its connections and networks to compensate for damage or loss. This process is called neural flexibility. However, in dementia, this flexibility becomes excessive and unstable. The brain’s networks start to reorganize more frequently, but these changes are not always helpful. Instead, they can make the brain’s communication less stable and more chaotic, making it harder to solve problems or think clearly [5].
The damage caused by dementia is not limited to just a few brain regions or networks. It affects the whole brain, including important structures like the hippocampus and the medial temporal lobe. These areas are crucial for memory and learning, but they also play a role in problem solving by helping the brain store and retrieve information. When these areas are damaged, people with dementia may have trouble remembering how to solve problems or learning new ways to do things [6].
Despite the challenges, researchers are working to understand how dementia affects the brain’s problem solving networks and to find ways to help people with dementia maintain their cognitive abilities. One approach is to use brain stimulation techniques, such as transcranial direct current stimulation (tDCS), to target specific networks and improve their function. Studies have shown that stimulating the dorsolateral prefrontal cortex, a key part of the executive function network, can help improve problem solving and other cognitive skills in people with dementia [4].
Another area of research focuses on using advanced imaging techniques to detect changes in brain networks before symptoms become severe. By analyzing the structure and function of brain networks, researchers can identify early signs of dementia and track how the disease progresses. This information can help doctors develop better treatments and interventions to support people with dementia and their families [6].
Dementia’s impact on the brain’s problem solving networks is complex and far-reaching. It affects not only the specific networks involved in planning and decision making but also the way these networks communicate and adapt. As the disease progresses, the brain’s ability to solve problems becomes increasingly impaired, making everyday tasks more difficult and challenging. Understanding these changes is crucial for developing effective treatments and support strategies for people with dementia.
[1] Nature Communications, Functional network collapse in neurodegenerative disease
[2] Frontiers in Psychiatry, Network analysis of cognition and function in Alzheimer’s disease
[3] Science Advances, Neurophysiological signatures of default mode network dysfunction
[4] NIH, Targeting the parietal memory network with tDCS in MCI
[5] PsyPost, Increased neural flexibility may signal brain network breakdown in Alzheimer’s
[6] Scientific Reports, Detection of brain network abnormalities by graph invariants in dementia
